GetCallIndex trait (#13558)

* GetCallIndex trait

* final impl

* ".git/.scripts/commands/fmt/fmt.sh"

* Docs

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* One more test

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Doc

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: command-bot <>
Co-authored-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

substrate/frame/support/procedural/src/lib.rs

@@ -984,7 +984,8 @@ pub fn compact(_: TokenStream, _: TokenStream) -> TokenStream {
 ///
 /// The macro creates an enum `Call` with one variant per dispatchable. This enum implements:
 /// [`Clone`], [`Eq`], [`PartialEq`], [`Debug`] (with stripped implementation in `not("std")`),
-/// `Encode`, `Decode`, `GetDispatchInfo`, `GetCallName`, and `UnfilteredDispatchable`.
+/// `Encode`, `Decode`, `GetDispatchInfo`, `GetCallName`, `GetCallIndex` and
+/// `UnfilteredDispatchable`.
 ///
 /// The macro implements the `Callable` trait on `Pallet` and a function `call_functions`
 /// which returns the dispatchable metadata.

substrate/frame/support/procedural/src/pallet/expand/call.rs

@@ -324,6 +324,21 @@ pub fn expand_call(def: &mut Def) -> proc_macro2::TokenStream {
 			}
 		}
 
+		impl<#type_impl_gen> #frame_support::dispatch::GetCallIndex for #call_ident<#type_use_gen>
+			#where_clause
+		{
+			fn get_call_index(&self) -> u8 {
+				match *self {
+					#( Self::#fn_name { .. } => #call_index, )*
+					Self::__Ignore(_, _) => unreachable!("__PhantomItem cannot be used."),
+				}
+			}
+
+			fn get_call_indices() -> &'static [u8] {
+				&[ #( #call_index, )* ]
+			}
+		}
+
 		impl<#type_impl_gen> #frame_support::traits::UnfilteredDispatchable
 			for #call_ident<#type_use_gen>
 			#where_clause

substrate/frame/support/src/dispatch.rs

@@ -29,7 +29,8 @@ pub use crate::{
 		result,
 	},
 	traits::{
-		CallMetadata, GetCallMetadata, GetCallName, GetStorageVersion, UnfilteredDispatchable,
+		CallMetadata, GetCallIndex, GetCallMetadata, GetCallName, GetStorageVersion,
+		UnfilteredDispatchable,
 	},
 };
 #[cfg(feature = "std")]

substrate/frame/support/src/traits.rs

@@ -74,8 +74,8 @@ pub use randomness::Randomness;
 
 mod metadata;
 pub use metadata::{
-	CallMetadata, CrateVersion, GetCallMetadata, GetCallName, GetStorageVersion, PalletInfo,
-	PalletInfoAccess, PalletInfoData, PalletsInfoAccess, StorageVersion,
+	CallMetadata, CrateVersion, GetCallIndex, GetCallMetadata, GetCallName, GetStorageVersion,
+	PalletInfo, PalletInfoAccess, PalletInfoData, PalletsInfoAccess, StorageVersion,
 	STORAGE_VERSION_STORAGE_KEY_POSTFIX,
 };
 

substrate/frame/support/src/traits/metadata.rs

@@ -101,12 +101,20 @@ pub struct CallMetadata {
 
 /// Gets the function name of the Call.
 pub trait GetCallName {
-	/// Return all function names.
+	/// Return all function names in the same order as [`GetCallIndex`].
 	fn get_call_names() -> &'static [&'static str];
 	/// Return the function name of the Call.
 	fn get_call_name(&self) -> &'static str;
 }
 
+/// Gets the function index of the Call.
+pub trait GetCallIndex {
+	/// Return all call indices in the same order as [`GetCallName`].
+	fn get_call_indices() -> &'static [u8];
+	/// Return the index of this Call.
+	fn get_call_index(&self) -> u8;
+}
+
 /// Gets the metadata for the Call - function name and pallet name.
 pub trait GetCallMetadata {
 	/// Return all module names.

substrate/frame/support/test/tests/pallet.rs

@@ -25,8 +25,8 @@ use frame_support::{
 	pallet_prelude::{StorageInfoTrait, ValueQuery},
 	storage::unhashed,
 	traits::{
-		ConstU32, GetCallName, GetStorageVersion, OnFinalize, OnGenesis, OnInitialize,
-		OnRuntimeUpgrade, PalletError, PalletInfoAccess, StorageVersion,
+		ConstU32, GetCallIndex, GetCallName, GetStorageVersion, OnFinalize, OnGenesis,
+		OnInitialize, OnRuntimeUpgrade, PalletError, PalletInfoAccess, StorageVersion,
 	},
 	weights::{RuntimeDbWeight, Weight},
 };
@@ -231,6 +231,12 @@ pub mod pallet {
 			Ok(().into())
 		}
 
+		#[pallet::call_index(4)]
+		#[pallet::weight(1)]
+		pub fn foo_index_out_of_order(_origin: OriginFor<T>) -> DispatchResult {
+			Ok(())
+		}
+
 		// Test for DispatchResult return type
 		#[pallet::call_index(2)]
 		#[pallet::weight(1)]
@@ -728,8 +734,25 @@ fn call_expand() {
 	assert_eq!(call_foo.get_call_name(), "foo");
 	assert_eq!(
 		pallet::Call::<Runtime>::get_call_names(),
-		&["foo", "foo_storage_layer", "foo_no_post_info", "check_for_dispatch_context"],
+		&[
+			"foo",
+			"foo_storage_layer",
+			"foo_index_out_of_order",
+			"foo_no_post_info",
+			"check_for_dispatch_context"
+		],
 	);
+
+	assert_eq!(call_foo.get_call_index(), 0u8);
+	assert_eq!(pallet::Call::<Runtime>::get_call_indices(), &[0u8, 1u8, 4u8, 2u8, 3u8])
+}
+
+#[test]
+fn call_expand_index() {
+	let call_foo = pallet::Call::<Runtime>::foo_index_out_of_order {};
+
+	assert_eq!(call_foo.get_call_index(), 4u8);
+	assert_eq!(pallet::Call::<Runtime>::get_call_indices(), &[0u8, 1u8, 4u8, 2u8, 3u8])
 }
 
 #[test]